One prior art rotary cutter uses an arrangement for clamping a cutting blade in a roll 18 as illustrated in FIG. 2. The blade 11 is mounted in a blade holder 13. Plural pairs of axially aligned set screws 15, and 17 apply a clamping force to the blade holder 13 in order to retain the blade 11 within the blade holder 13. The blade holder 13 is mounted within cut out 19 in the roll 18. The thickness of the cut out 19 is larger than the thickness of the blade holder 13 which allows the position and direction of the blade holder to change down the length of the roll. Since the blade holder 13 is flexible, when all of the pairs of set screws 15, 17 have been adjusted, the shape of the cutting edge of the blade 11 will not necessarily be a straight line. One disadvantage of the prior art clamping arrangement is caused by the fact that the set screws 15, 17 do not have perfectly flat faces but tend to concentrate the clamping force about a relatively small area surrounding the axes 23 of the set screws 15, 17. As a result, any force, as represented by the arrow 27, acting on the blade 11 not only bends the blade 11 but tends to rotate the blade holder 13 about axis 29, which runs along the length of blade 12, and intersects the axes of set screws 15 and 17. In addition, because the slot 31 in blade holder 13 must be larger than the thickness of the blade 11, even when the blade 11 is clamped, there is some tendency for the plane of the blade 11 to pivot about the axis 29. Because of this tendency of the plane of the blade 11 and blade holder 13 to rotate about an axis parallel to the length of the blade 11, that portion of the blade 11 that projects from blade holder 13 does not resist the force F in a true built-in cantilever fashion.
I have found that it is desirable to have a blade holder that minimizes the tendency of the clamped portion of the blade to rotate about an axis parallel to the length of the blade in response to bending forces F acting on the blade 11.